Paris (AFP): Iranian security forces cracked down on a student protest overnight at a top Tehran university amid the wave of women-led demonstrations sparked by the death of Mahsa Amini, rights groups said Monday.

Kurdish Iranian Amini, 22, was pronounced dead on September 16, days after the notorious morality police detained her for allegedly breaching rules forcing women to wear hijab headscarves and modest clothes.

Outrage over her death has sparked the biggest wave of protests to rock the Islamic republic in almost three years, as well as global solidarity rallies that saw people take to the streets in more than 150 cities at the weekend, with many symbolically cutting off their hair.

Concern grew over the latest violence at Tehran's prestigious Sharif University of Technology where, local media reported, riot police confronted hundreds of students, with officers using tear gas and paintball guns and carrying non-lethal steel pellet guns.

"Woman, life, liberty," students shouted, as well as "students prefer death to humiliation", Mehr news agency reported, adding that Iran's science minister, Mohammad Ali Zolfigol, came to speak to the students in a bid to calm the situation.

As protests stretch into a third week, with unrest also reported at the University of Isfahan and elsewhere, ultra-conservative President Ebrahim Raisi on Sunday said that the "enemies" of Iran had "failed in their conspiracy".

Iran has accused outside forces of stoking the protests, especially the United States and its allies, and last week said nine foreign nationals -- including from France, Germany, Italy, the Netherlands and Poland -- had been arrested.

"Hard to bear what is happening at #SharifUniversity in #Iran," German Foreign Minister Annalena Baerbock tweeted on Monday. "The courage of the Iranians is incredible. And the regime's brute force is an expression of sheer fear of the power of education and freedom."

Oslo-based group Iran Human Rights posted video apparently showing Iranian police on motorcycles pursuing students running through an underground car park and, in a separate clip, taking away detainees whose heads were covered in black cloth bags.

'Don't be afraid'
In other footage, which AFP has not independently verified, shooting and screaming can be heard as large numbers of people run down a street at night.

In one clip, which IHR said was taken at a Tehran metro station, a crowd can be heard chanting: "Don't be afraid! Don't be afraid! We are all together!"

The New York-based Center for Human Rights in Iran said it was "extremely concerned by videos coming out of Sharif University and Tehran today showing violent repression of protests + detainees being hauled away with their heads completely covered in fabric".

Mehr news agency said that Sharif University of Technology had "announced that due to recent events and the need to protect students ... all classes will be held virtually from Monday".

At least 92 protesters have been killed so far in the Mahsa Amini rallies, said IHR, which has been working to assess the death toll despite internet outages and blocks on WhatsApp, Instagram and other online services.

London-based Amnesty International said earlier it had confirmed 53 deaths, after Iran's semi-official Fars news agency said last week that "around 60" people had died.

The chief of riot police in Marivan, Kurdistan province, died of his wounds Sunday night after being shot during "riots", state television said Monday -- the 12th death reported among the security forces since September 16.

An additional 41 people died in clashes Friday in Iran's southeastern Sistan-Baluchestan province, bordering Afghanistan and Pakistan, IHR reported citing local sources.

Those protests were sparked by accusations a police chief in the region had raped a teenage girl of the Baluch Sunni minority, the rights group said.

Tehran has said five Revolutionary Guards members were killed in the unrest Friday in Zahedan, the capital of Sistan-Baluchestan, which also often sees clashes with Baluchi minority rebels, Sunni Muslim extremist groups and drug smuggling gangs.